Introduction:
From Jan 1, 2007 all ISBN will transfer from 10 digit to 13 digital.
The check digit algorithm of the check digit is also changed.
Introduction:
From Jan 1, 2007 all ISBN will transfer from 10 digit to 13 digital.
The check digit algorithm of the check digit is also changed.
Algorithm:
The calculation of an ISBN-13 check digit begins with the first 12 digits
of the 13-digit ISBN (thus excluding the check digit itself).
Each digit from left to right is multiplied alternately by 1 or 3,
then these products are summed modulo 10 to give a value from 0 to 9.
Subtracted from 10, this leaves a result from 1 to 10. A 10 is replaced by a 0,
so in all cases a single check digit emerges.
Example:
the ISBN-13 check digit of 978-0-306-40615-? is calculated as follows
s = 9×1 + 7×3 + 8×1 + 0×3 + 3×1 + 0×3 + 6×1 + 4×3 + 0×1 + 6×3 + 1×1 + 5×3 = 9 + 21 + 8 + 0 + 3 + 0 + 6 + 12 + 0 + 18 + 1 + 15 = 93 93 / 10 = 9 remainder 3 10 – 3 = 7
Thus the check digit is 7, and the complete sequence is ISBN 978-0-306-40615-7.